Epothilone derivatives

ABSTRACT

The present invention relates to compounds of the formula 
                         
where the variables are as defined in the disclosure.

RELATED APPLICATIONS

This application is a continuation of, and claims the benefit ofpriority of application Ser. No. 11/512,623, filed Aug. 30, 2006 (nowU.S. Pat. No. 7,241,755), which is a continuation of Ser. No.10/405,886, filed Apr. 3, 2003 (now U.S. Pat. No. 7,125,899), which is acontinuation of, and claims the benefit of priority of application Ser.No. 09/084,542, filed May 26, 1998 (now U.S. Pat. No. 6,650,599), whichclaims priority to U.S. provisional application Ser. No. 60/067,524,filed Dec. 4, 1997, and provisional application Ser. No. 60/051,951,filed Jul. 8, 1997.

FIELD OF THE INVENTION

The present invention relates to epothilone derivatives, methods for thepreparation of the derivatives and intermediates therefor.

BACKGROUND OF THE INVENTION

Epothilones are macrolide compounds which find utility in thepharmaceutical field. For example, Epothilones A and B having thestructures:

have been found to exert microtubule-stabilizing effects similar toTAXOL and hence cytotoxic activity against rapidly proliferating cells,such as, tumor cells or other hyperproliferative cellular disease, seeAngew. Chem. Int. Ed. Engl., 1996, 35, No. 13/14.

SUMMARY OF THE INVENTION

The present invention relates to compounds of the formula

wherein,

Q is selected from the group consisting of

G is selected from the group consisting of alkyl, substituted alkyl,substituted or unsubstituted aryl, heterocyclo,

W is O or NR₁₅;

X is O or H,H;

Y is selected from the group consisting of O; H,OR₁₆; OR₁₇,OR₁₇; NOR₁₈;H,NOR₁₉; H,NR₂₀R₂₁; H,H; or CHR₂₂; OR₁₇OR₁₇ can be a cyclic ketal;

Z₁ and Z₂ are selected from the group consisting of CH₂, O, NR₂₃, S, andSO₂, wherein only one of Z and Z₂ is a heteroatom;

B₁ and B₂ are selected from the group consisting of OR₂₄, or OCOR₂₅, orO₂CNR₂₆R₂₇; when B₁ is H and Y is OH, H they can form a six-memberedring ketal or acetal;

D is selected from the group consisting of NR₂₈R₂₉, NR₃₀COR₃₁ orsaturated heterocycle;

R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₁₃, R₁₄, R₁₈, R₁₉, R₂₀, R₂₁, R₂₂, R₂₆, andR₂₇ are selected from the group H, alkyl, substituted alkyl, or aryl andwhen R₁ and R₂ are alkyl can be joined to form a cycloalkyl; R₃ and R₄are alkyl can be joined to form a cycloalkyl;

R₉, R₁₀, R₁₆, R₁₇, R₂₄, R₂₅, and R₃₁ are selected from the group H,alkyl, or substituted alkyl;

R₈, R₁₁, R₁₂, R₂₈, R₃₀, R₃₂, R₃₃, and R₃₀ are selected from the groupconsisting of H, alkyl, substituted alkyl, aryl, substituted aryl,cycloalkyl, or heterocyclo;

R₁₅, R₂₃ and R₂₉ are selected from the group consisting of H, alkyl,substituted alkyl, aryl, substituted aryl, cycloalkyl, heterocyclo,R₃₂C═O, R₃₃SO₂, hydroxy, O-alkyl or O-substituted alkyl;

and any salts, solvates or hydrates thereof.

Proviso

The present invention does not include compounds of formula V wherein

W and X are both O; and

R₁, R₂, R₇, are H; and

R₃, R₄, R₆, are methyl; and

R₈, is H or methyl; and

Z₁, and Z₂, are CH₂; and

G is 1-methyl-2-(substituted-4-thiazolyl)ethenyl; and

Q is as defined above.

DETAILED DESCRIPTION OF THE INVENTION

Listed below are definitions of various terms used to describe thisinvention. These definitions apply to the terms as they are usedthroughout this specification, unless otherwise limited in specificinstances, either individually or as part of a larger group.

The term “alkyl” refers to straight or branched chain unsubstitutedhydrocarbon groups of 1 to 20 carbon atoms, preferably 1 to 7 carbonatoms. The expression “lower alkyl” refers to unsubstituted alkyl groupsof 1 to 4 carbon atoms.

The term “substituted alkyl” refers to an alkyl group substituted by,for example, one to four substituents, such as, halo, trifluoromethyl,trifluoromethoxy, hydroxy, alkoxy, cycloalkoxy, heterocyclooxy, oxo,alkanoyl, aryloxy, alkanoyloxy, amino, alkylamino, arylamino,aralkylamino, cycloalkylamino, heterocycloamino, disubstituted amines inwhich the 2 amino substituents are selected from alkyl, aryl or aralkyl,alkanoylamino, aroylamino, aralkanoylamino, substituted alkanoylamino,substituted arylamino, substituted aralkanoylamino, thiol, alkylthio,arylthio, aralkylthio, cycloalkylthio, heterocyclothio, alkylthiono,arylthiono, aralkylthiono, alkylsulfonyl, arylsulfonyl, aralkylsulfonyl,sulfonamido (e.g. SO₂NH₂), substituted sulfonamido, nitro, cyano,carboxy, carbamyl (e.g. CONH₂), substituted carbamyl (e.g. CONH alkyl,CONH aryl, CONH aralkyl or cases where there are two substituents on thenitrogen selected from alkyl, aryl or aralkyl), alkoxycarbonyl, aryl,substituted aryl, guanidino and heterocyclos, such as, indolyl,imidazolyl, furyl, thienyl, thiazolyl, pyrrolidyl, pyridyl, pyrimidyland the like. Where noted above where the substituent is furthersubstituted it will be with halogen, alkyl, alkoxy, aryl or aralkyl.

The term “halogen” or “halo” refers to fluorine, chlorine, bromine andiodine.

The term “aryl” refers to monocyclic or bicyclic aromatic hydrocarbongroups having 6 to 12 carbon atoms in the ring portion, such as phenyl,naphthyl, biphenyl and diphenyl groups, each of which may besubstituted.

The term “aralkyl” refers to an aryl group bonded directly through analkyl group, such as benzyl.

The term “substituted aryl” refers to an aryl group substituted by, forexample, one to four substituents such as alkyl, substituted alkyl,halo, trifluoromethoxy, trifluoromethyl, hydroxy, alkoxy, cycloalkyloxy,heterocyclooxy, alkanoyl, alkanoyloxy, amino, alkylamino, aralkylamino,cycloalkylamino, heterocycloamino, dialkylamino, alkanoylamino, thiol,alkylthio, cycloalkylthio, heterocyclothio, ureido, nitro, cyano,carboxy, carboxyalkyl, carbamyl, alkoxycarbonyl, alkylthiono,arylthiono, alkysulfonyl, sulfonamido, aryloxy and the like. Thesubstituent may be further substituted by halo, hydroxy, alkyl, alkoxy,aryl, substituted aryl, substituted alkyl or aralkyl.

The term “cycloalkyl” refers to optionally substituted, saturated cyclichydrocarbon ring systems, preferably containing 1 to 3 rings and 3 to 7carbons per ring which may be further fused with an unsaturated C₃-C₇carbocyclic ring. Exemplary groups include cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl,cyclododecyl, and adamantyl. Exemplary substituents include one or morealkyl groups as described above, or one or more groups described aboveas alkyl substituents.

The terms “heterocycle”, “heterocyclic” and “heterocyclo” refer to anoptionally substituted, fully saturated or unsaturated, aromatic ornonaromatic cyclic group, for example, which is a 4 to 7 memberedmonocyclic, 7 to 11 membered bicyclic, or 10 to 15 membered tricyclicring system, which has at least one heteroatom in at least one carbonatom-containing ring. Each ring of the heterocyclic group containing aheteroatom may have 1, 2 or 3 heteroatoms selected from nitrogen atoms,oxygen atoms and sulfur atoms, where the nitrogen and sulfur heteroatomsmay also optionally be oxidized and the nitrogen heteroatoms may alsooptionally be quaternized. The heterocyclic group may be attached at anyheteroatom or carbon atom.

Exemplary monocyclic heterocyclic groups include pyrrolidinyl, pyrrolyl,indolyl, pyrazolyl, oxetanyl, pyrazolinyl, imidazolyl, imidazolinyl,imidazolidinyl, oxazolyl, oxazolidinyl, isoxazolinyl, isoxazolyl,thiazolyl, thiadiazolyl, thiazolidinyl, isothiazolyl, isothiazolidinyl,furyl, tetrahydrofuryl, thienyl, oxadiazolyl, piperidinyl, piperazinyl,2-oxopiperazinyl, 2-oxopiperidinyl, 2-oxopyrrolidinyl, 2-oxazepinyl,azepinyl, 4-piperidonyl, pyridyl, N-oxo-pyridyl, pyrazinyl, pymidinyl,pyridazinyl, tetrahydropyranyl, tetrahydrothiopyranyl,tetrahydrothiopyranyl sulfone, morpholinyl, thiomorpholinyl,thiomorpholinyl sulfoxide, thiomorpholinyl sulfone, 1,3-dioxolane andtetrahydro-1, 1-dioxothienyl, dioxanyl, isothiazolidinyl, thietanyl,thiiranyl, triazinyl, and triazolyl, and the like.

Exemplary bicyclic heterocyclic groups include benzothiazolyl,benzoxazolyl, benzothienyl, quinuclidinyl, quinolinyl,quinolinyl-N-oxide, tetrahydroisoquinolinyl, isoquinolinyl,benzimidazolyl, benzopyranyl, indolizinyl, benzofuryl, chromonyl,coumarinyl, cinnolinyl, quinoxalinyl, indazolyl, pyrrolopyridyl,furopyridinyl (such as furo[2,3-c]pyridinyl, furo[3,1-b]pyridinyl, orfuro[2,3-b]pyridinyl), dihydroisoindolyl, dihydroquinazolinyl (such as3,4-dihydro-4-oxo-quinazolinyl), benzisothiazolyl, benzisoxazolyl,benzodiazinyl, benzofurazanyl, benzothiopyranyl, benzotriazolyl,benzpyrazolyl, dihydrobenzofuryl, dihydrobenzothienyl,dihydrobenzothiopyranyl, dihydrobenzothiopyranyl sulfone,dihydrobenzopyranyl, indolinyl, isochromanyl, isoindolinyl,naphthyridinyl, phthalazinyl, piperonyl, purinyl, pyridopyridyl,quinazolinyl, tetrahydroquinolinyl, thienofuryl, thienopyridyl,thienothienyl, and the like.

Exemplary substituents include one or more alkyl groups as describedabove or one or more groups described above as alkyl substituents. Alsoincluded are smaller heterocyclos, such as, epoxides and aziridines.

The term “heteroatoms” shall include oxygen, sulfur and nitrogen.

The compounds of formula V may form salts with alkali metals such assodium, potassium and lithium, with alkaline earth metals such ascalcium and magnesium, with organic bases such as dicyclohexylamine,tributylamine, pyridine and amino acids such as arginine, lysine and thelike. Such salts can be obtained, for example, by exchanging thecarboxylic acid protons, if they contain a carboxylic acid, in compoundsof formula V with the desired ion in a medium in which the saltprecipitates or in an aqueous medium followed by evaporation. Othersalts can be formed as known to those skilled in the art.

The compounds for formula V form salts with a variety of organic andinorganic acids. Such salts include those formed with hydrogen chloride,hydrogen bromide, methanesulfonic acid, hydroxyethanesulfonic acid,sulfuric acid, acetic acid, trifluoroacetic acid, maleic acid,benzenesulfonic acid, toluenesulfonic acid and various others (e.g.,nitrates, phosphates, borates, tartrates, citrates, succinates,benzoates, ascorbates, salicylates and the like). Such salts are formedby reacting a compound of formula V in an equivalent amount of the acidin a medium in which the salt precipitates or in an aqueous mediumfollowed by evaporation.

In addition, zwitterions (“inner salts”) are formed.

Compounds of the formula V may also have prodrug forms. Any compoundthat will be converted in vivo to provide the bioactive agent (i.e., thecompound for formula V) is a prodrug within the scope and spirit of theinvention.

For example compounds of the formula V may form a carboxylate estermoiety. The carboxylate esters are conveniently formed by esterifyingany of the carboxylic acid functionalities found on the disclosed ringstructure(s).

Various forms of prodrugs are well known in the art. For examples ofsuch prodrug derivatives, see:

a) Design of Prodrugs, edited by H. Bundgaard, (Elsevier, 1985) andMethods in Enzymology, Vol. 112, pp. 309-396, edited by K. Widder et al.(Academic Press, 1985);

b) A Textbook of Drug Design and Development, edited by Krosgaard-Larsenand H. Bundgaard, Chapter 5, “Design and Application of Prodrugs,” by H.Bundgaard, pp. 113-191 (1991);

c) H. Bundgaard, Advanced Drug Delivery Reviews, 8, pp. 1-38 (1992);

d) H. Bundgaard et al., Journal of Pharmaceutical Sciences, 77, p. 285(1988); and

e) N. Kakeya et al., Chem. Phar. Bull, 32, p. 692 (1984).

It should further be understood that solvates (e.g., hydrates) of thecompounds of formula V are also within the scope of the presentinvention. Methods of solvation are generally known in the art.

Use and Utility

The compounds of formula V are microtubule-stabilizing agents. They arethus useful in the treatment of a variety of cancers or other abnormalproliferative diseases, including (but not limited to) the following;

-   -   carcinoma, including that of the bladder, breast, colon, kidney,        liver, lung, ovary, pancreas, stomach, cervix, thyroid and skin;        including squamous cell carcinoma;    -   hematopoietic tumors of lymphoid lineage, including leukemia,        acute lymphocytic leukemia, acute lymphoblastic leukemia, B-cell        lymphoma, T-cell lymphoma, Hodgkins lymphoma, non-Hodgkins        lymphoma, hairy cell lymphoma and Burketts lymphoma;    -   hematopoietic tumors of myeloid lineage, including acute and        chronic myelogenous leukemias and promyelocytic leukemia;    -   tumors of mesenchymal origin, including fibrosarcoma and        rhabdomyoscarcoma;    -   other tumors, including melanoma, seminoma, tetratocarcinoma,        neuroblastoma and glioma;    -   tumors of the central and peripheral nervous system, including        astrocytoma, neuroblastoma, glioma, and schwannomas;    -   tumors of mesenchymal origin, including fibrosarcoma,        rhabdomyoscaroma, and osteosarcoma; and    -   other tumors, including melanoma, xenoderma pigmentosum,        keratoactanthoma, seminoma, thyroid follicular cancer and        teratocarcinoma.

Compounds of formula V may also inhibit tumor angiogenesis, therebyaffecting abnormal cellular proliferation. Such anti-angiogenesisproperties of the compounds of formula V may also be useful in thetreatment of certain forms of blindness related to retinalvascularization, arthritis, especially inflammatory arthritis, multiplesclerosis, restinosis and psoriasis.

Compounds of formula V may induce or inhibit apoptosis, a physiologicalcell death process critical for normal development and homeostasis.Alterations of apoptotic pathways contribute to the pathogenesis of avariety of human diseases. Compounds of formula V, as modulators ofapoptosis, will be useful in the treatment of a variety of humandiseases with aberrations in apoptosis including cancer (particularly,but not limited to follicular lymphomas, carcinomas with p53 mutations,hormone dependent tumors of the breast, prostrate and ovary, andprecancerous lesions such as familial adenomatous polyposis), viralinfections (including but not limited to herpesvirus, poxvirus,Epstein-Barr virus, Sindbis virus and adenovirus), autoimmune diseases(including but not limited to systemic lupus erythematosus, immunemediated glomerulonephritis, rheumatoid arthritis, psoriasis,inflammatory bowel diseases and autoimmune diabetes mellitus),neurodegenerative disorders (including but not limited to Alzheimer'sdisease, AIDS-related dementia, Parkinson's disease, amyotrophic lateralsclerosis, retinitis pigmentosa, spinal muscular atrophy and cerebellardegeneration), AIDS, myelodysplastic syndromes, aplastic anemia,ischemic injury associated myocardial infarctions, stroke andreperfusion injury, arrhythmia, atherosclerosis, toxin-induced oralcohol induced liver diseases, hematological diseases (including butnot limited to chronic anemia and aplastic anemia), degenerativediseases of the musculoskeletal system (including but not limited toosteoporosis and arthritis), aspirin-sensitive rhinosinusitis, cysticfibrosis, multiple sclerosis, kidney diseases, and cancer pain.

The compounds of this invention are also useful in combination withknown anti-cancer and cytotoxic agents and treatments, includingradiation. If formulated as a fixed dose, such combination productsemploy the compounds of this invention within the dosage range describedbelow and the other pharmaceutically active agent within its approveddosage range. Compounds of formula V can be used sequentially with knownanticancer or cytotoxic agents and treatment, including radiation when acombination formulation is inappropriate. Especially useful arecytotoxic drug combinations wherein the second drug chosen acts in adifferent phase of the cell cycle, e.g. S phase, than the presentcompounds of formula V which exert their effects at the G₂-M phase.

-   e.g. Thymidilate Synthase Inhibitors

DNA Cross Linking Agents

Topoisomerase I and II Inhibitors

DNA Alkylating Agents

Ribonucleoside Reductase Inhibitors

Cytotoxic Factors e.g. TNF-alpha or

Growth factor inhibitors e.g. HER 2 receptor MAB's

The present compounds may exist as multiple optical, geometric, andstereoisomers. Included within the present invention are all suchisomers and mixtures thereof.

The compounds of this invention can be formulated with a pharmaceuticalvehicle or diluent for oral, intravenous or subcutaneous administration.The pharmaceutical composition can be formulated in a classical mannerusing solid or liquid vehicles, diluents and additives appropriate tothe desired mode of administration. Orally, the compounds can beadministered in the form of tablets, capsules, granules, powders and thelike. The compounds are administered in a dosage range of about 0.05 to200 mg/kg/day, preferably less than 100 mg/kg/day, in a single dose orin 2 to 4 divided doses.

Preferred Compounds

Especially preferred compounds of formula V are those wherein,

Q is

X is O;

Y is O;

Z₁ and Z₂ are CH₂; and

W is NR₁₅.

Method of Preparation

Compounds of formula V are prepared by the following schemes.

wherein R₃, R₄, R₅, R₆, R₈ and R₁₅ are as above and P₁ is an oxygenprotecting group.

Compounds of formula V where W is NR₁₅ and X is O can be prepared asoutlined in Scheme 1. A compound of formula XII, where P₁ is an oxygenprotecting group such as t-butyldimethylsilyl, can be prepared from acompound of formula VI by known methods (i.e., Nicolaou, K. C. et al.,Angew. Chem. Int. Ed. Engl., 36:166-168 (1997)). Aldol reaction of acompound of formula XII and a compound of formula XIV provides acompound of formula XIII. The compound of formula XIV can be prepared byknown methods (i.e., Schinzer, D. et al., Eur. Chem. Chron., 1:7-10(1996)). An aldehyde of formula XVIII can be prepared from a compound offormula XV as shown in Scheme 1 or by using known methods (i.e., Taylor,R. E. et al., Tetrahedron Lett., 38:2061-2064 (1997)). A compound offormula XIX can be prepared from a compound XVIII by treatment with anamine using dehydrating conditions such as catalytic p-toluenesulfonicacid and azeotropic removal of water. A compound of formula XX can beprepared from a compound of formula XIX by treatment with an allylatingreagent such as allylmagnesium bromide. A compound of formula XXI can beprepared from compounds of formulas XIII and XX, by standard amide bondcoupling agents (i.e., DCC, BOP, EDC/HOBT, PyBrOP). A compound offormula XXII can be prepared from a compound of formula XXI byring-closing metathesis using either the Grubbs (RuCl₂(═CHPh)(PCY₃)₂;see Grubbs, R. H. et al., Angew. Chem. Int. Ed. Engl., 34:2039 (1995))or Schrock catalysts (See Schrock, R. R. et al., J. Am. Chem. Soc.,112:3875 (1990)). Deprotection of a compound of formula XXI using, forexample when P₁ is a t-butyldimethylsily group, hydrogen fluoride inacetronitrile or tetra-n-butyl ammonium fluoride in THF provides acompound of formula V where Q is an ethylene group, W is NR₁₅, X is O,an R₃, R₄, R₅, R₆ are defined as described above. Regioselectiveepoxidation of a compound of formula V where Q is an ethylene groupusing dimethyldioxirane provides a compound of formula V where Q is anoxirane group, W is NR₁₅, X is O, and R₃, R₄, R₅, R₁₅ are defined asdescribed above.

Alternatively, a compound of formula VIII can be prepared by reaction ofa compound of formula XXIII with magnesium and an acid chloride(R₅CH₂COCl) to give a compound of formula XXIV (See for example:Heathcock, C. et al., J. Org. Chem., 55:1114-1117 (1990)), followed byozononolysis to give a compound of formula VIII as shown in Scheme 2.

Alternatively, a compound of formula XIV can be prepared as shown inScheme 3. Reaction of a compound of formula XXV and pseudoephedrineprovides a compound of formula XXVI. A compound of formula XXVII can beprepared from a compound of formula XXVI by alkylation with a pentenylhalide such as 5-bromopentene according to the method of Meyers (i.e.,Meyers, A. et al., J. Am. Chem. Soc., 116:9361-9362 (1994)). A compoundof formula XXVIII can be prepared from a compound of formula XXVII witha reducing agent such as lithium pyrrolidinyl borohydride. Oxidation ofa compound of formula XXVIII, using for example pyridiniumchlorochromate, provides a compound of formula XIV. Direct conversion ofa compound of formula XXVII to a compound of formula XIV can beaccomplished with a reducing agent such as lithium triethoxy-aluminumhydride.

Alternatively, a compound of formula XX can be prepared fromallylglycine as shown in Scheme 4. Allylglycine can be N-protected usingmethods known in the art to give a compound of formula XXIX, where P₂ isa suitable N-protecting group such as t-butyloxycarbonyl. Optionally,where R₂₉ is not hydrogen, a compound of formula XXX can be preparedfrom a compound of formula XXIX by alkylation with an alkyl halide inthe presence of a base such as sodium hydride. A compound of formulaXXXI can be prepared from a compound of formula XXX usingN,O-dimethylhydroxylamine and standard coupling agents such as EDCI andHOBT. A compound of formula XXXII can be prepared from a hydroxamateXXXI by treatment with an organometallic reagent such as an alkyl orarylmagnesium halide. Wittig olefination of a compound of formula XXXIIprovides a compound of formula XXXIII (the Wittig reagent is prepared asreported: Danishefsky, S. E. et al., J. Org. Chem., 61:7998-7999(1996)). N-Deprotection of a compound of formula XXXIII using methodsknown in the art provides a compound of formula XX.

A compound of formula V where W is NR₁₅, X is oxygen, and G is a1,2-disubstituted olefin can be prepared as shown in Scheme 5. Acompound of formula XXXV can be prepared by Wittig olefination of acompound of formula XXXII. A compound of formula XXXIV can be preparedby methods known in the art. A compound of formula XXXVI can be preparedby N-deprotection of a compound of formula XXXV using methods known inthe art. A compound of formula XXXVII can be prepared by couplingreaction of a compound of formula XXXVI and a compound of formula XIIIusing standard coupling agents such as EDCI and HOBT. A compound offormula XXXVIII can be prepared from a compound of formula XXXVII bymethods described in Scheme 1 for the preparation of a compound offormula XXII. Using methods described in Scheme 1 (steps o and p), acompound of formula XXXVIII can be converted to compounds of formula Vwhere W is NR₁₅, X is oxygen, and G is a 1,2-disubstituted olefin.

A compound of formula V where both W and X are oxygen, and G is a1,2-disubstituted olefin can be prepared as shown in Scheme 6. Acompound of formula XXXX can be prepared from a compound of formulaXXXIX by treatment with an allylating agent such as allylmagnesiumbromide. Enantiomerically pure XXXX can be prepared by employing chiralreagents (see, for example: Taylor, R. E. et al., Tetrahedron Lett.,38:2061-2064 (1997); Nicolaou, K. C. et al., Angew. Chem. Int. Ed.Engl., 36:166-168 (1997); Keck, G. et al., J. Am. Chem. Soc., 115:8467(1993)). A compound of formula XXXXI can be prepared from compounds offormula XXXX and XIII by using standard esterification methods such asDCC and DMAP. A compound of formula XXXXII can be prepared from acompound of formula XXXXI via ring-closing olefin metathesis asdescribed in Scheme 1 for the preparation of a compound of formula XXII.Compounds of formula V where both W and X are oxygen, and G is a1,2-disubstituted olefin can be prepared from a compound of formulaXXXXII by deprotection (where Q is an ethylene group) and, if desired,epoxidation (where Q is an oxirane group) as described above.

A compound of formula V where both W and X are oxygen, and G is alkyl,substituted alkyl, aryl, heteroaryl, bicycloaryl, or bicycloheteroarylcan be prepared as shown in Scheme 7. A compound of formula XXXXIV canbe prepared by allylation of a compound of formula XXXXIII, where G isalkyl, substituted alkyl, aryl, heteroaryl, bicycloaryl, orbicycloheteroaryl, by reaction with an allylating reagent such as allylmagnesium bromide. A compound of formula XXXXV can be prepared from acompound of formula XXXXIV via esterification with a compound of formulaXIII using, for example, DCC and DMAP. A compound of formula XXXXVI canbe prepared from a compound of formula XXXXV by ring-closing metathesisas described above. Following the methods outlined above for Scheme 1, acompound of formula XXXXVI can be converted to compounds of formula V bydeprotection and subsequent epoxidation.

A compound of formula V where W is NR₁₅, X is oxygen, and G is alkyl,substituted alkyl, aryl, heteroaryl, bicycloaryl, or bicycloheteroarylcan be prepared as shown in Scheme 8. A compound of formula XXXXVII canbe prepared by reaction of a compound of formula XXXXIII, where G isalkyl, substituted alkyl, aryl, heteroaryl, bicycloaryl, orbicycloheteroaryl, and an amine under dehydrating conditions. A compoundof formula XXXXVIII can be prepared from a compound of formula XXXXVIIby treatment with an allylating agent such as allylmagnesium bromide. Acompound of formula XXXXIX can be prepared from a compound of formulaXXXXVIII and a compound of formula XIII by standard amide bond couplingtechniques using, for example, EDCI and HOBT. A compound of formula Lcan be prepared from a compound of formula XXXXIX by ring-closingmetathesis as described above. Following the methods outlined above forScheme 1, a compound of formula L can be converted to compounds offormulas V by deprotection and subsequent epoxidation.

A compound of formula V where X is oxygen, W is NR₁₅, and G is

and D is selected from the group consisting of NR₂₈R₂₉, NR₃₀COR₃₁, andsaturated heterocycle (i.e., piperidinyl, morpholinyl, piperazinyl,etc.) can be prepared as shown in Scheme 9. A compound of formula LI canbe prepared from a compound of 10 formula XXXII by reductive aminationusing a primary or secondary amine and a reducing agent such as sodiumtriacetoxyborohydride. Compounds of formula LIII, LIV, and V can then beprepared following methods described above in Scheme 1.

Alternatively, a compound of formula V where X is oxygen, W is oxygen orNR₁₅, and G is

and D is selected from the group consisting of NR₂₈R₂₉, NR₃₀COR₃₁, andsaturated heterocycle (i.e., piperidinyl, morpholinyl, piperazinyl,etc.) can be prepared from a compound of formula V as shown in Scheme10. A compound of formula V can be converted to a compound of formula LVby protection of the hydroxyl groups with suitable protecting groupssuch as t-butyldimethylsilyl. A compound of formula LVI can be preparedfrom a compound of formula LV by ozonolysis. Treatment of a compound offormula LVI with an amine and a reducing agent such as sodiumtriacetoxyboro-hydride provides a compound of formula LVII. Removal ofthe protecting groups from a compound of formula LVII, with for examplehydrogen fluoride, provides a compound of formula V where X is oxygen, Wis NR₁₅ or oxygen, and G is

A compound of formula V where W is NR₁₅, X is oxygen, and G is

can be prepared as outlined in Scheme 11. A compound of formula LVIIIcan be prepared from a compound of formula XXX by treatment with anamine and standard amide bond coupling agents such as EDCI and HOBT. Acompound of formula LX can be prepared from a compound of formula LVIIIby N-deprotection, using for example trifluoroacetic acid when P₂ is at-butyloxycarbonyl group, followed by coupling of compounds of formulaLIX and XIII using standard amide bond coupling agents such as EDCI andHOBT. A compound of formula LXI can be prepared from a compound offormula LX by ring-closing metathesis. A compound of formula V can beprepared from a compound of formula LXI following methods described inScheme 1.

A compound of formula V where W is oxygen, X is oxygen, and G is

can be prepared as outlined in Scheme 12. A compound of formula LXII canbe prepared from allylglycine by treatment with nitrous acid. A compoundof formula LXIII can be prepared from a compound of formula LXII bytreatment with an amine and standard amide bond coupling agents such asEDCI and HOBT. A compound of formula LXIV can be prepared from compoundsof formula LXIII and XIII using standard amide bond coupling agents suchas EDCI and HOBT. A compound of formula LXV can be prepared from acompound of formula LXIV by ring-closing metathesis. A compound offormula V can be prepared from a compound of formula LXV followingmethods described in Scheme 1.

Compounds of formula V where G is a 1,2-disubstituted ethyl group can beprepared from a compound of formula V where G is a 1,2-disubstitutedethylene group by hydrogenation with a catalyst such as palladium oncarbon, as shown in Scheme 13. Furthermore, compounds of formula V whereG is a 1,2-disubstituted cyclopropyl group can be prepared from acompound of formula V where G is a 1,2-disubstituted ethylene group bycyclopropanation with diiodomethane and zinc-copper couple, as shown inScheme 13.

A compound of formula V where Z₁ is oxygen can be prepared as shown inScheme 14. A compound of formula LXVII can be prepared from analpha-hydroxy ester LXVI and a 3-buten-1-yl-trifluoromethanesulfonate(or with a 3-butenyl bromide and silver triflate). A compound of formulaLXVII can be reduced with a reducing agent such as diisobutylaluminumhydride to provide a compound of formula LXVIII. Alternatively, acompound of formula LXVIII can be obtained from a compound of formulaLXVII by a two step procedure involving reduction with lithiumborohydride and oxidation with pyridinium chlorochromate. This compoundof formula LXVIII can be substituted for a compound of formula XIV inScheme 1 to give a compound of formula LXIX. Further elaboration of LXIXas described above provides a compound of formula V where Z₁ is oxygen.

Similarly, a compound of formula V where Z₁ is NR₂₃ can be prepared asshown in Scheme 15. A compound of formula LXXI can be prepared from analpha-amino ester LXX and a 3-buten-1-yl-bromide. A compound of formulaLXXI can be reduced with a reducing agent such as diisobutylaluminumhydride to provide a compound of formula LXXII. Alternatively, acompound of formula LXXII can be obtained from a compound of formulaLXXI by a two step procedure involving reduction with lithiumborohydride and oxidation with pyridinium chlorochromate. This compoundof formula LXXII can be substituted for a compound of formula XIV inScheme 1 to give a compound of formula LXXIII. Further elaboration ofLXXIII as described above provides a compound of formula V where Z₁ isNR₂₃.

A compound of formula V where Z₂ is oxygen can be prepared as shown inScheme 16. A compound of formula LXXV can be prepared from abeta-hydroxy ester LXXIV and an allylating agent such as allylbromide(or an allyl bromide and silver triflate). A compound of formula LXXVcan be reduced with a reducing agent such as diisobutylaluminum hydrideto provide a compound of formula LXXVI. Alternatively, a compound offormula LXXVI can be obtained from a compound of formula LXXV by a twostep procedure involving reduction with lithium borohydride andoxidation with pyridinium chlorochromate. This compound of formula LXXVIcan be substituted for a compound of formula XIV in Scheme 1 to give acompound of formula LXXVII. Further elaboration of LXXVII as describedabove provides a compound of formula V where Z₂ is oxygen.

Similarly, a compound of formula V where Z₂ is NR₂₃ can be prepared asshown in Scheme 17. A compound of formula LXXIX can be prepared from abeta-amino ester LXXVIII and an allylating agent such as allylbromide. Acompound of formula LXXIX can be reduced with a reducing agent such asdiisobutylaluminum hydride to provide a compound of formula LXXX.Alternatively, a compound of formula LXXX can be obtained from acompound of formula LXXIX by a two step procedure involving reductionwith lithium borohydride and oxidation with pyridinium chlorochromate.This compound of formula LXXX can be substituted for a compound offormula XIV in Scheme 1 to give a compound of formula LXXXI. Furtherelaboration of LXXXI as described above provides a compound of formula Vwhere Z₂ is NR₂₃.

A compound of formula V where W is oxygen or NR₁₅ and X is H,H can beprepared as shown in Scheme 18. A compound of formula V can be convertedto a compound of formula LXXXII, where P₄ and P₅ are hydroxyl protectinggroups, by treatment with a reagent such ast-butyldimethylsilyltriflate. A compound of formula LXXXIII can beprepared from a compound of formula LXXXII by treatment with Lawesson'sreagent. A compound of formula LXXXIV can be prepared from a compound offormula LXXXIII by using a reducing agent such as tri-n-butyltin hydridewhen W is oxygen or by treatment with methyl iodide and sodiumborohydride when W is NR₁₅. Removal of the protecting groups from acompound of formula LXXXIV, using for example hydrogen fluoride when P₄and P₅ are silyl groups, provides a compound of formula V where W isoxygen or NR₁₅ and X is H,H.

A compound of formula V where W, X and Y are oxygen, and R₁ is alkyl orsubstituted alkyl can be prepared as shown in Scheme 19. A compound offormula V can be protected to give a compound of formula LXXXXV, whereP₅ and P₆ are hydroxyl protecting groups, by treatment with a reagentsuch as t-butyldimethylsilyl trifluoromethanesulfonate. A compound offormula LXXXXVI can be prepared from a compound of formula LXXXXV bytreatment with a reducing agent such as sodium borohydride. A compoundof formula LXXXXVII can be prepared from a compound of formula LXXXXVIby protection of the hydroxyl group, where P₇ is for examplep-methoxybenzyl, using p-methoxybenzyl trichloroacetimidate. Removal ofthe protecting groups P₅ and P₆ of a compound of formula LXXXXVII using,for example, hydrogen fluoride in pyridine when P₅ and P₆ aret-butyldimethylsilyl groups provides a compound of formula LXXXXVIIIwhich then can be selectively protected using for examplet-butyldimethylsilyl chloride to give a compound of formula LXXXXIXwhere P₈ is a t-butyldimethylsilyl group. A compound of formula C can beprepared from a compound of formula LXXXXIX by treatment with a basesuch as lithium diisopropylamide followed by treatment with analkylating agent such as methyl iodide. A compound of formula C can beprotected to give a compound of formula CI, where P₉ is a hydroxylprotecting group, by treatment with a reagent such ast-butyldimethylsilyl trifluoromethanesulfonate. A compound of formulaCII can be prepared from a compound of formula CI by removal of the P₇group using, for example, DDQ when P₇ is a p-methoxybenzyl group. Acompound of formula V, where W, X and Y are oxygen, and R₁ is alkyl orsubstituted alkyl, can be prepared from a compound of formula CII byoxidation using, for example, TPAP/NMO followed by removal of theprotecting groups using, for example, hydrogen fluoride when P₈ and P₉are silyl groups. This compound of formula V can be further oxidizedwith dimethyldioxirane as shown in Scheme 1 to provide the correspondingepoxide compound of formula V.

A compound of formula V where X is oxygen and Q is an olefin can beprepared from a compound of formula V where X is oxygen and Q is anoxirane ring by treatment with a reactive metallocene such astitanocene, zirconocene or niobocene as shown in Scheme 20 (see forexample R. Schobert and U. Hohlein, Synlett, 465-466 (1990)).

A compound of formula V where X is oxygen and W is NR₁₅, where R₁₅ ishydrogen, can be prepared from a compound of formula V where both X andW are oxygen as shown in Scheme 21. A compound of formula CIII can beprepared from a compound of formula V where both X and W are oxygen byformation of pi-allylpalladium complex using, for example, palladiumtetrakistriphenylphosphine followed by treatment with sodium azide (see,for example: Murahashi, S.-I. et al., J. Org. Chem., 54:3292 (1989)).Subsequent reduction of a compound of formula CIII with a reducing agentsuch as triphenylphosphine provides a compound of formula CIV. Acompound of formula V where X is oxygen and W is NR₁₅, where R₁₅ ishydrogen, can be prepared from a compound of formula CIV bymacrolactamization using, for example, diphenylphosphoryl azide orbromotripyrrolidinophosphonium hexafluorophosphate (PyBroP).

A compound of formula V where X is oxygen and W is NR₁₅, where R₁₅ isalkyl, substituted alkyl, aryl, heteroaryl, cycloalkyl, heterocyclo,O-alkyl, O-substituted alkyl, can be prepared from a compound of formulaV where both X and W are oxygen as shown in Scheme 22. A compound offormula CV can be prepared from a compound of formula V where both X andW are oxygen by formation of pi-allylpalladium complex using, forexample, palladium tetrakistriphenylphosphine followed by treatment witha primary amine. A compound of formula V where X is oxygen and W is NR₁₅where R₁₅ is alkyl, substituted alkyl, aryl, heteroaryl, cycloalkyl,heterocyclo, OH, O-alkyl, O-substituted alkyl, can be prepared from acompound of formula CV by macrolactamization using, for example,diphenylphosphoryl azide or bromotripyrrolidinophosphoniumhexafluorophosphate (PyBroP). In the case where R₁₅ is OH, it may benecessary to remove a protecting group such as t-butyldimethylsilyl froman intermediate where R₁₅ is O-t-butyldimethylsilyl.

The in vitro assessment of biological activity of the compounds ofFormula V was performed as follows:

In vitro Tubulin Polymerization

Twice cycled (2×) calf brain tubulin was prepared following theprocedure of Williams and Lee (see Williams, R. C., Jr. and Lee, J. C.,“Preparation of tubulin from brain.”, Methods in Enzymology, 85, Pt. D,376-385 (1982)) and stored in liquid nitrogen before use. Quantificationof tubulin polymerization potency is accomplished following a modifiedprocedure of Swindell et al. (see Swindell, C. S., Krauss, N. E.,Horwitz, S. B. and Ringel, I., “Biologically active taxol analogues withdeleted A-ring side chain substituents and variable C-2′configurations.”, J. Med. Chem., 34:1176-1184 (1991)). Thesemodifications, in part, result in the expression of tubulinpolymerization potency as an effective concentration for any givencompound. For this method, different concentrations of compound inpolymerization buffer (0.1M MES, 1 mM EGTA, 0.5 mM MgCl₂, pH 6.6) areadded to tubulin in polymerization buffer at 37° in microcuvette wellsof a Beckman (Beckman Instruments) Model DU 7400 TN spectrophotometer. Afinal microtubule protein concentration of 1.0 mg/ml and compoundconcentration of generally 2.5, 5.0, and 10 μM are used. Initial slopesof OD change measured every 10 seconds were calculated by the programaccompanying the instrument after initial and final times of the linearregion encompassing at least 3 time points were manually defined. Underthese conditions linear variances were generally <10⁻⁶, slopes rangedfrom 0.03 to 0.002 absorbance unit/minute, and maximum absorbance was0.15 absorbance units. Effective concentration (EC_(0.01)) is defined asthe interpolated concentration capable of inducing an initial slope of0.01 OD/minute rate and is calculated using the formula:EC_(0.01)=concentration/slope. EC_(0.01) values are expressed as themean with standard deviation obtained from 3 different concentrations.EC_(0.01) values for the compounds in this invention fall in the range0.01-1000 μM.

Cytoxicity (In-Vitro)

Cytoxicity was assessed in HCT-116 human colon carcinoma cells by MTS(3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphenyl)-2H-tetrazolium,inner salt) assay as reported in T. L. Riss et al., “Comparison of MTT,XTT, and a novel tetrazolium compound MTS for in vitro proliferation andchemosensitivity assays.”, Mol. Biol. Cell, 3 (Suppl.):184a (1992).Cells were plated at 4,000 cell/well in 96 well microtiter plates and 24hours later drugs were added and serial diluted. The cells wereincubated at 37° form 72 hours at which time the tetrazolium dye, MTS at333 μg/ml (final concentration), in combination with the electroncoupling agent phenazine methosulfate at 25 μM (final concentration) wasadded. A dehydrogenase enzyme in live cells reduces the MTS to a formthat absorbs light at 492 nM which can be quantitatedspectrophotometrically. The greater the absorbance the greater thenumber of live cells. The results are expressed as an IC₅₀, which is thedrug concentration required to inhibit cell proliferation (i.e.absorbance at 450 nM) to 50% of that of untreated control cells. TheIC₅₀ values for compounds of this invention fall in the range 0.01-1000nM.

EXAMPLES

The following Examples illustrate the present invention.

Example 1

[4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-Dihydroxy-5,5,7,9-tetramethyl-16-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-1-aza-13(E)-cyclohexadecene-2,6-dioneA. N-[(2-Methyl)-1-propenyl]morpholine

To stirring morpholine (165.5 g, 1.9 mol) was added isobutyraldehyde(173 mL, 1.9 mol) at a rate which did not allow the temperature of thereaction to exceed 30° C. After complete addition, the reaction mixturewas stirred at room temperature for 2 h, and then the flask was equippedwith a Dean-Stark trap and heated at 160° C. for 20 h. The reactionmixture was then cooled to room temperature, and the flask was equippedwith a vigreux column distillation apparatus. Distillation under highvacuum gave 135 g (50%) of Compound A as a clear colorless oil. MS (M+H,142).

B. 2,2-Dimethyl-3-oxopentanal

To a stirring solution of propionyl chloride (44 mL, 0.50 mol) in ether(135 mL) at 0° C. under nitrogen was added a solution of Compound A (69g, 0.50 mol) in ether (135 mL) over 45 min. After addition was complete,the reaction mixture was stirred at reflux for 2 h, and then stirred atroom temperature for 16 h. The reaction mixture was filtered, and thefilter cake was washed with ether (50 mL). The volatiles were removed invacuo. The residue was taken into H₂O (80 mL) and the solution wasadjusted to a pH of 4. Ether was added (80 mL) and the biphasic mixturewas stirred for 16 h. The reaction mixture was poured into a separatoryfunnel, the layers separated, and the aqueous layer was extracted withether (5×100 mL). The combined organics were dried (MgSO₄), filtered,and evaporated in vacuo. The residue was distilled under high vacuum togive 10.4 g (16%) of Compound B as a clear, colorless oil. MS (M−H,127).

C. 4-tert-Butyldimethylsilyloxy-5,5-dimethyl-6-oxo-1-octene

To a solution of (−)-B-methoxydiisopinocamphenylborane (25.7 g, 81 mmol)in ether (80 mL) at 0° C. under nitrogen was added 1.0 M allylmagnesiumbromide in ether (77 mL, 77 mmol) over 1.5 h. The reaction mixture wasstirred at 25° C. for 1 h, and then concentrated in vacuo. The residuewas extracted with pentane (2×150 mL), and the extracts were filteredthrough Celite under nitrogen. The combined extracts were thenevaporated in vacuo to give the B-allyldiisopinocamphenylborane. Thismaterial was taken up in ether (200 mL) and cooled to −100° C. undernitrogen. A solution of Compound B (11.42 g, 89 mmol) in ether (90 mL)at −78° C. was then added over a 1 h period. The reaction mixture wasstirred for an additional 0.5 h and methanol (1.5 mL) was added. Thereaction mixture was brought to room temperature, treated with 3 N NaOH(32 mL) and 30% H₂O₂ (64 mL), and then kept at reflux for 2 h. Thereaction mixture was cooled to room temperature, the layers wereseparated, and the organic phase was washed with H₂O (500 mL). Thecombined aqueous washes were re-extracted with ether (2×100 mL). Thecombined organic extracts were washed with saturated aqueous NaCl (100mL), dried (MgSO₄), filtered, and concentrated in vacuo. This residuewas taken up in CH₂Cl₂ (250 mL), cooled to 0° C., anddiisopropylethylamine (93 mL, 535 mmol) was added. To the stirringsolution was then added tert-butyldimethylsilyltrifluoromethanesulfonate (69 g, 260 mmol) slowly as to not increase thetemperature above 10° C. After complete addition, the reaction mixturewas poured into H₂O (650 mL), the layers were separated, and the aqueouslayer was extracted with CH₂Cl₂ (2×650 mL). The combined organics weredried (Na₂SO₄), filtered, and concentrated in vacuo. The residue waspurified by flash chromatography eluting with hexanes followed by 10%EtOAc/hexanes to give 17.2 g (78%) of Compound C as a clear, colorlessoil. The enantiomeric excess was found to be 94% determined by ¹H NMRanalysis of the Mosher's ester of the alcohol. ¹³C NMR (CDCl₃, 80 MHz) d215.8, 136.1, 116.5, 52.8, 39.0, 31.9, 26.0, 22.4, 20.1, 18.1, 7.6,−3.6, −4.4.

D. 3-tert-Butyldimethylsiloxy-4,4-dimethyl-5-oxoheptanal

Through a solution of Compound C (10.8 g, 38.0 mmol) in CH₂Cl₂ at −78°C. was bubbled O₃ until the solution remained blue (1 h). O₂ was thenbubbled through for 15 min followed by N₂ for 30 min after which timethe solution became clear. Triphenylphosphine (10 g, 38 mmol) was thenadded and the reaction mixture was warmed to −35° C. and stored for 16h. The volatiles were removed in vacuo and the residue was purified byflash chromatography eluting with 8% EtOAc/hexanes to give 8.9 g (74%)of Compound D as a clear, colorless oil. ¹H NMR (CDCl₃, 300 MHz) d 9.75(m, 1H), 4.53 (t, J=4.8 Hz, 1H), 3.40-3.60 (m, 4H), 1.10 (s, 3H), 1.07(s, 3H), 0.98 (t, J=7.0 Hz, 3H), 0.83 (s, 9H), 0.07 (s, 3H), 0.04 (s,3H).

E. 3-tert-Butyldimethylsiloxy-4,4-dimethyl-5-oxoheptanoic acid

To a solution of Compound D (3.90 g, 13.6 mmol) in t-butanol (75 mL) wasadded 2-methyl-2-butene (5.85 mL, 55.2 mmol), and then a solution ofsodium chlorite (4.61 g, 40.8 mmol) and sodium phosphate monobasic (2.81g, 20.4 mmol) in H₂O (15 mL) was added dropwise at room temperature. Thereaction mixture was stirred for 0.5 h and then the solvents wereremoved in vacuo. To the residue was added H₂O (150 mL) followed byextraction with EtOAc (3×150 mL). The combined organic extracts weredried (MgSO₄), filtered, and the volatiles were removed in vacuo. Theresidue was purified by flash chromatography eluting with 20%EtOAc/hexanes/1% AcOH to give 3.79 g (92%) of Compound E as a clear,colorless, viscous oil. MS (M+H, 303).

F.(R,R)-N-(2-Hydroxy-1-methyl-2-phenethyl)-N,2-(S)-dimethyl-6-hepteneamide

A suspension of LiCl (6.9 g, 0.16 mol) and preformed lithiumdiisopropylamide (Aldrich, 2.0 M solution in heptane/ethylbenzene/THF,27.6 mL, 55 mmol) in additional THF (70 mL) at −78° C. was treateddropwise with a solution of(R,R)-N-(2-hydroxy-1-methyl-2-phenylethyl)-N-methyl propionamide (6.0 g,27 mmol, Meyers, A. G. et al., J. Am. Chem. Soc., 116:9361 (1994)) inTHF (30 mL) over 10 min. The bright yellow, reaction mixture was stirredat −78° C. (1 h), at 0° C. (15 min), and at 25° C. (5 min) before beingrecooled to 0° C. and treated with a solution of 5-bromo-1-pentene (4.8mL, 40 mmol) in THF (5 mL). The reaction mixture was stirred at 0° C.(24 h), poured into saturated aqueous NH₄Cl (100 mL) and EtOAc (100 mL).The two phases were separated and the aqueous phase was furtherextracted with EtOAc (3×100 mL). The organic extracts were combined,washed with saturated aqueous NaCl (200 mL), dried (Na₂SO₄), andconcentrated in vacuo. Flash chromatography (SiO₂, 4.0×25 cm, 2%MeOH—CHCl₃) afforded Compound F (6.9 g, 88%) as a pale yellow oil. MS(ESI⁺): 290 (M+H)⁺; MS(ESI⁻): 288.2 (M−H)⁻.

G. (S)-2-Methyl-6-heptenol

A 250 mL round-bottom flask at 0° C. was charged sequentially withpyrrolidine (2.6 mL, 30 mmol) and BH₃-THF complex (1.0 M in THF, 31 mL,30 mmol). The borane-pyrrolidine complex was warmed to 25° C. (1 h),recooled to 0° C., and treated with n-butyllithium (1.6 M in hexane, 19mL, 30 mmol) dropwise over 30 min while carefully maintaining aninternal temperature below 5.5° C. The reaction mixture was stirred at0° C. for an additional 30 min before a solution of Compound F (3.0 g,10 mmol) in THF (23 mL) was added dropwise over 10 min. The reactionmixture was stirred at 25° C. (6 h) before being quenched by thedropwise addition of aqueous 3 N HCl (25 mL). The reaction mixture wasthen poured into aqueous 1 N HCl (200 mL) and extracted with Et₂O (4×80mL). The combined organics were washed with a 1:1 solution of saturatedaqueous NaCl-aqueous 1 N HCl (2×150 mL) and concentrated in vacuo. Anaqueous solution of NaOH (1 N, 200 mL) was added to the residue and thesuspension was stirred for 30 min. The mixture was extracted with Et₂O(3×100 mL) and the combined ether layers were washed with a 1:1 solutionof saturated aqueous NaCl—aqueous 1 N NaOH (2×200 mL), dried (Na₂SO₄),and concentrated in vacuo. Flash chromatography (SiO₂, 4.0×25 cm, 15-25%Et₂O-pentane gradient elution) afforded Compound G (1.26 g, 95%) as acolorless oil. [a]²⁵ _(D)−11 (c 12, CH₂Cl₂).

H. (S)-2-Methyl-6-heptenal

A solution of Compound G (0.24 g, 1.9 mmol) in CH₂Cl₂ (6 mL) was treatedwith pyridinium chlorochromate (0.61 g, 2.8 mmol) and the reactionmixture was stirred at 25° C. for 5 h. The resulting dark brown viscousslurry was passed through a silica gel-Celite plug (Celite 1.0×1 cm ontop of SiO₂, 1.0×5 cm, eluting with 50 mL of CH₂Cl₂). The solvent wasremoved in vacuo to afford crude Compound H (0.15 g, 63%) as a colorlessoil, which was sufficiently pure to use in subsequent reactions. ¹H NMR(300 MHz, CD₂Cl₂) d 9.62 (s, 1H), 5.88-5.68 (m, 1H), 5.13-4.92 (m, 2H),2.37-2.24 (m, 1H), 2.15-2.05 (m, 2H), 1.62-1.78 (m, 1H), 1.51-1.32 (m,3H), 1.07 (d, 3H, J=7.0 Hz).

I.(3S,6R,7S,8S)-3-tert-Butyldimethylsiloxy-4,4,6,8-tetramethyl-7-hydroxy-5-oxo-12-tridecenoicacid

To a preformed LDA solution (Aldrich, 2.0 M solution inheptane/ethylbenzene/THF, 3.8 mL, 7.6 mmol) in additional THF (25 mL) at−78° C. was added a solution of Compound E (1.0 g, 3.4 mmol) in THF (5mL) dropwise over 3 min. The reaction mixture was stirred at −78° C. (10min), warmed to −40° C. (20 min), and recooled to −78° C. beforeCompound H (0.56 g, 4.4 mmol) in THF (5 mL) was added. The reactionmixture was warmed to −40° C., stirred for 1 h, and diluted withsaturated aqueous NH₄Cl (50 mL). The two layers were separated and theaqueous phase was extracted with EtOAc (4×50 mL). The combined organiclayers were washed with saturated aqueous NaCl (100 mL), dried (Na₂SO₄),and concentrated in vacuo. Flash chromatography (SiO₂, 2.5×20 cm, 2-5%MeOH—CHCl₃ gradient elution) followed by HPLC (YMC S-10, ODS, 30×500 mmcolumn, eluting with MeOH at a flow rate of 20 mL/min) separationafforded the desired syn-aldol product Compound I (0.60 g, 43%) and anundesired diastereomer (0.32 g, 22%) along with starting Compound E(˜10%). MS (ESI⁺): 879.3 (2M+Na)⁺, 451.2 (M+Na)⁺, 429.2 (M+H)⁺;MS(ESI⁻): 427.3 (M−H)⁻. Stereochemistry was confirmed by directcomparison of both the ¹³C and ¹H NMRs of the subsequent esterderivative (used in the synthesis of Epothilone C) to the sameintermediate previously described by K. C. Nicolaou et al., Angew. Chem.Int. Ed. Engl, 36:166 (1997).

J. (S)-2-[N-[(tert-Butyloxy)carbonyl]amino]-4-pentenoic acid

A solution L-2-amino-4-pentenoic acid (NovaBiochem, 3.0 g, 26 mmol) inTHF-H₂O (1:1, 200 mL) at 0° C. was treated sequentially with NaHCO₃ (6.6g, 78 mmol) and di-tert-butyl dicarbonate (10.4 g, 1.8 mmol). Thereaction mixture was warmed to 25° C. and stirred for 16 h. The pH ofthe mixture was adjusted to 4 by the careful addition of saturatedaqueous citric acid at 0° C., and the mixture was extracted with EtOAc(4×50 mL). The combined organic layers were washed with saturatedaqueous NaCl (75 mL), dried (Na₂SO₄), and concentrated in vacuo. Flashchromatography (SiO₂, 4.0×6 cm, 5-10% MeOH—CHCl₃ gradient elution)afforded Compound J (5.5 g, 99%) as a colorless oil. MS(ESI⁻): 429.3(2M−H)⁻, 214.1 (M−H)⁻.

K.(S)-2-[N²-[(tert-Butyloxy)carbonyl]amino]-N-methoxy-N-methyl-4-penteneamide

A solution Compound J (2.9 g, 13 mmol) in CHCl₃ (55 mL) at 0° C. wastreated sequentially with N,O-dimethylhydroxylamine hydrochloride (1.4g, 15 mmol), 1-hydroxybenzotriazole (2.0 g, 15 mmol), 4-methylmorpholine(4.4 mL, 40 mmol), and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimidehydrochloride (3.4 g, 18 mmol). The reaction mixture was graduallywarmed to 25° C., stirred for 16 h, and diluted with H₂O (100 mL). Thetwo layers were separated and the aqueous phase was extracted with EtOAc(3×75 mL). The combined organic phases were washed with aqueous 5% HCl(100 mL), saturated aqueous NaHCO₃ (100 mL), saturated aqueous NaCl (100mL), dried (Na₂SO₄), and concentrated in vacuo. Flash chromatography(SiO₂, 3.0×20 cm, 25-50% EtOAc-hexane gradient elution) affordedCompound K (2.5 g, 71%) as a colorless oil. MS (ESI⁺): 258.9 (M+H)⁺,202.9 (M-isobutylene) 158.9 (M-BOC); MS(ESI⁻): 257.2 (M−H)⁻.

L. (S)-3-[N-[(tert-Butyloxy)carbonyl]amino]-5-hexen-2-one

A solution of Compound K (2.5 g, 1.0 mmol) in THF (65 mL) at 0° C. wastreated with methylmagnesium bromide (3.0 M in Et₂O, 8.1 mL, 2.4 mmol).The reaction mixture was stirred at 0° C. (2.5 h) and carefully pouredinto saturated aqueous NH₄Cl (100 mL). The two layers were separated andthe aqueous phase was extracted with EtOAc (3×75 mL). The combinedorganic extracts were washed with saturated aqueous NH₄Cl (75 mL), H₂O(75 mL), saturated aqueous NaCl (75 mL), dried (MgSO₄), and concentratedin vacuo. Flash chromatography (SiO₂, 3.0×20 cm, 10-25% EtOAc-hexanegradient elution) afforded(S)-2-[N-[(tert-Butyloxy)carbonyl]amino]-5-hexene-2-one (2.2 g, 67%) asa colorless oil. MS (ESI⁺): 213.9 (M+H)⁺, 157.9 (M-isobutylene), 113.9(M−BOC); MS(ESI⁻): 212.2 (M−H⁻).

M.(S)-4-[3-[N-[(tert-Butyloxy)carbonyl]amino]-2-methyl-1(E),5-hexadienyl]-2-methylthiazole

A solution of 2-methyl-4-thiazolylmethyl diphenylphosphine oxide (2.5 g,8.0 mmol, Danishefsky et al., J. Org. Chem., 61:7998 (1996)) in THF (38mL) at −78° C. was treated with n-butyllithium (1.6 M in hexane, 5.2 mL,8.4 mmol) dropwise over 5 min. The resulting brilliant orange mixturewas stirred for 15 min at −78° C., and treated with a solution ofCompound L (0.81 g, 3.8 mmol) in THF (5 mL). After 10 min at −78° C.,the cooling bath was removed and the reaction mixture was allowed towarm to 25° C. (2 h). The mixture was poured into saturated aqueousNH₄Cl (50 mL) and the two layers were separated. The aqueous phase wasextracted with Et₂O (3×50 mL) and the combined organic extracts werewashed successively with H₂O (75 mL), saturated aqueous NaHCO₃ (75 mL),saturated aqueous NaCl (75 mL), dried (Na₂SO₄), and concentrated invacuo. Flash chromatography (SiO₂, 4.0×30 cm, 10-20% EtOAc-hexanegradient elution) afforded Compound M (0.23 g, 18%) as a colorless oilalong with recovered starting ketone (20-30%). MS (ESI⁺): 309.1 (M+H)⁺,253.0 (M−isobutylene); MS(ESI⁻): 307.3 (M−H)⁻.

N. (S)-4-(3-Amino-2-methyl-1(E),5-hexadienyl-2-methylthiazole

Compound M (0.15 g, 0.49 mmol) was treated with 4.0 N HCl in 1,4-dioxane(5 mL) at 0° C. (30 min) under Ar. The volatiles were removed in vacuo,and the resulting white foam was dissolved in cold saturated aqueousNaHCO₃ (3 mL). The solution was extracted with EtOAc (4×10 mL), and thecombined EtOAc layers were dried (Na₂SO₄) and concentrated in vacuo.Flash chromatography (SiO₂, 1.0×5 cm, 5-10% MeOH—CHCl₃ gradient elution)afforded Compound N (88 mg, 88%) as a colorless oil. MS (ESI⁺): 209.0(M+H)⁺; MS(ESI⁻): 207.2 (M−H)⁻.

O.(3S,6R,7S,8S)-N-(S)-[1-(2-Methyl-4-thiazolyl-2-methyl-1(E),5-hexadien-3-yl]-3-tert-butyldimethylsiloxy-4,4,6,8-tetramethyl-7-hydroxy-5-oxo-12-trideceneamide

A solution of Compound N (88 mg, 0.42 mmol) in DMF (1.3 mL) at 0° C. wastreated sequentially with Compound I (0.15 g, 0.35 mmol),1-hydroxybenzotriazole (49 mg, 0.36 mmol), and1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.10 g,0.52 mmol). The reaction mixture was gradually warmed to 25° C., stirredfor 15 h, and diluted with H₂O (3 mL). The mixture was extracted withEtOAc (3×10 mL), and the combined organic phases were washed withaqueous 5% HCl (10 mL), saturated aqueous NaHCO₃ (10 mL), saturatedaqueous NaCl (10 mL), dried (Na₂SO₄), and concentrated in vacuo. Flashchromatography (SiO₂, 1.5×20 cm, 2.5% MeOH—CHCl₃) afforded Compound O(0.17 g, 77%) as a white foam. MS (ESI⁺): 619.3 (M+H)⁺.

P.[4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4-tert-Butyldimethylsiloxy-8-hydroxy-5,5,7,9-tetramethyl-16-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-1-aza-13(E)-cyclohexadecene-2,6-dione

A solution of Compound O (17 mg, 27 mmol) in degassed benzene (8.0 mL)was treated with Grubb's catalystbis(tricyclohexyl-phosphine)benzylidine-ruthenium dichloride, StremChemicals, 11 mg, 14 mmol) under Ar. The reaction mixture was stirred at25° C. for 15 h and treated again with an additional portion of catalyst(5.0 mg, 4.5 mmol). After 7 additional hours, the benzene was removed invacuo, and the black viscous residue was passed through a pad of silicagel (1.0×3 cm) eluting with Et₂O (25 mL). The eluent was concentrated invacuo to afford a separable 5:1 (E/Z) mixture of geometric isomers. PTLC(SiO₂, 1 mm plate, 2 elutions with a 1:1:1 solution ofhexane-toluene-ethyl acetate) afforded the E-isomer Compound P (5.1 mg,34%) and the corresponding Z-isomer (1.0 mg, 6.7%). For Compound P: MS(ESI⁻): 1181.7 (2M+H)⁺, 591.4 (M+H)⁺. For the Z-isomer: MS (ESI⁺):1181.5 (2M+H)⁺, 613.2 (M+Na)⁺, 591.2 (M+H)⁺; MS (ESI⁺): 589.3 (M−H)⁻.

Q.[4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-Dihydroxy-5,5,7,9-tetramethyl-16-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-1-aza-13(E)-cyclohexadecene-2,6-dione

To a 1 dram vial charged with Compound P (2.3 mg, 3.9 mmol) in CH₂Cl₂(0.4 mL) at 0° C. was added trifluoroacetic acid (0.1 mL). The reactionmixture was sealed under a blanket of Ar and stirred at 0° C. After 4 h,the volatiles were removed under a constant stream of Ar at 0° C.Saturated aqueous NaHCO₃ (1 mL) and EtOAc (1 mL) were added to theresidue and the two layers were separated. The aqueous phase wasextracted with EtOAc (4×1 mL), and the combined EtOAc layers were dried(Na₂SO₄) and concentrated in vacuo. PTLC (SiO₂, 20×10×0.025 cm, elutingwith 5% MeOH—CHCl₃) afforded[4S-[4R*,7S*,8S*,9R*,15R*(E)]]-4,8-dihydroxy-5,5,7,9-tetramethyl-16-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-1-aza-13(E)-cyclohexadecene-2,6-dione(1.3 mg, 68%) as a white film. MS (ESI⁺): 953.5 (2M+H)⁺, 477.3 (M+H)⁺;MS (ESI⁻): 475.5 (M−H)⁻.

Example 2

The following compounds can be made following the reaction schemespreviously disclosed:

-   [1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-dihydroxy-8,8,10,12,16-pentamethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-4,13,17-trioxabicyclo[14.1.0]heptadecane-5,9-dione;-   [1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-dihydroxy-8,8,10,12-tetramethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-4,13,17-trioxabicyclo[14.1.0]heptadecane-5,9-dione;-   [4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-dihydroxy-5,5,7,9,13-pentamethyl-16-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-1,10-dioxa-13-cyclohexadecene-2,6-dione;-   [4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-dihydroxy-5,5,7,9-tetramethyl-16-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-1,10-dioxa-13-cyclohexadecene-2,6-dione;-   [1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-dihydroxy-8,8,10,12,16-pentamethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-4,14,17-trioxabicyclo[14.1.0]heptadecane-5,9-dione;-   [1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-dihydroxy-8,8,10,12-tetramethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-4,14,17-trioxabicyclo[14.1.0]heptadecane-5,9-dione;-   [4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-dihydroxy-5,5,7,9,13-pentamethyl-16-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-1,11-dioxa-13-cyclohexadecene-2,6-dione;-   [4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-dihydroxy-5,5,7,9-tetramethyl-16-[1-methyl-2-(2-methyl-4-thizolyl)ethenyl]-1,11-dioxa-13-cyclohexadecene-2,6-dione;-   [1S-[1R*,3R*(E),7R*,10    S*,11R*,12R*,16S*]]-7,11-dihydroxy-8,8,10,12,16-pentamethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-4,17-dioxabicyclo[14.1.0]heptadecane-9-one;-   [1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-dihydroxy-8,8,10,12-tetramethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-4,17-dioxabicyclo[14.1.0]heptadecane-9-one;-   [1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-dihydroxy-3,8,8,10,12,16-hexamethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-4,17-dioxabicyclo[14.1.0]heptadecane-5,9-dione;-   [1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-dihydroxy-3,8,8,10,12-pentamethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-4,17-dioxabicyclo[14.1.0]heptadecane-5,9-dione;-   [4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-dihydroxy-5,5,7,9,13,16-hexamethyl-16-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-1-oxa-13-cyclohexadecene-2,6-dione;-   [4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-dihydroxy-5,5,7,9,16-pentamethyl-16-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-1-oxa-13-cyclohexadecene-2,6-dione;-   [1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-dihydroxy-6,8,8,10,12,16-hexamethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-4,17-dioxabicyclo[14.1.0]heptadecane-5,9-dione;-   [1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-dihydroxy-6,8,8,10,12-pentamethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-4,17-dioxabicyclo[14.1.0]heptadecane-5,9-dione;-   [4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-dihydroxy-5,5,7,9-tetramethyl-16-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-1-aza-13-cyclohexadecene-2,6-dione;-   [1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-dihydroxy-4,8,8,10,12,16-hexamethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-4-aza-17-oxabicyclo[14.1.0]heptadecane-5,9-dione;-   [1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-dihydroxy-4,8,8,10,12-pentamethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-4-aza-17-oxabicyclo[14.1.0]heptadecane-5,9-dione;-   [4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-dihydroxy-1,5,5,7,9,13-hexamethyl-16-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-1-aza-13-cyclohexadecene-2,6-dione;-   [4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-dihydroxy-1,5,5,7,9-pentamethyl-16-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-1-aza-13-cyclohexadecene-2,6-dione;-   [1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-dihydroxy-8,8,10,12,16-pentamethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-13-aza-4,17-dioxabicyclo    [14.1.0]heptadecane-5,9-dione;-   [1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-dihydroxy-8,8,10,12-tetramethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-13-aza-4,17-dioxabicyclo    [14.1.0]heptadecane-5,9-dione;-   [4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-dihydroxy-5,5,7,9,13-pentamethyl-16-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-10-aza-1-oxa-13-cyclohexadecene-2,6-dione;-   [4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-dihydroxy-5,5,7,9-tetramethyl-16-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-10-aza-1-oxa-13-cyclohexadecene-2,6-dione;-   [1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-dihydroxy-8,8,10,12,16-pentamethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-14-aza-4,17-dioxabicyclo[14.1.0]heptadecane-5,9-dione;-   [1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-dihydroxy-8,8,10,12-tetramethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-14-aza-4,17-dioxabicyclo    [14.1.0]heptadecane-5,9-dione;-   [4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-dihydroxy-5,5,7,9,13-pentamethyl-16-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-11-aza-1-oxa-13-cyclohexadecene-2,6-dione;-   [4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-dihydroxy-5,5,7,9-tetramethyl-16-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-11-aza-1-oxa-13-cyclohexadecene-2,6-dione;-   [1S-[1R*,3R*,7R*,10S*,11R*,12R*,16S*]]-N-phenyl-7,11-dihydroxy-8,8,10,12,16-pentamethyl-5,9-dioxo-4,17-dioxabicyclo    [14.1.0]heptadecane-3-carboxamide;-   [1S-[1R*,3R*,7R*,10S*,11R*,12R*,16S*]]-N-phenyl-7,11-dihydroxy-8,8,10,12-tetramethyl-5,9-dioxo-4,17-dioxabicyclo[14.1.0]heptadecane-3-carboxamide;-   [4S-[4R*,7S*,8R*,9R*,15R*]]-N-phenyl-4,8-dihydroxy-5,5,7,9,13-pentamethyl-2,6-dioxo-1-oxa-13-cyclohexadecene-16-carboxamide;-   [4S-[4R*,7S*,8R*,9R*,15R*]]-N-phenyl-4,8-dihydroxy-5,5,7,9-tetramethyl-2,6-dioxo-1-oxa-13-cyclohexadecene-16-carboxamide;-   [1S[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-dihydroxy-8,8,10,12,16-pentamethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)cyclopropyl]-4,17-dioxabicyclo[14.1.0]heptadecane-5,9-dione;    and-   [1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-dihydroxy-8,8,10,12-tetramethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)cyclopropyl]-4,17-dioxabicyclo    [14.1.0]heptadecane-5,9-dione.

Example 3

[1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-Dihydroxy-8,8,10,12,16-pentamethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-4-aza-17-oxabicyclo[14.1.0]heptadecane-5,9-dione A.(3S,6R,7S,8S,12R,13S,15S)-15-Azido-12,13-epoxy-4,4,6,8,12,16-hexamethyl-7-hydroxy-17-(2-methyl-4-thiazolyl)-5-oxo-16-heptadecenoicacid

A solution of epothilone B (0.35 g, 0.69 mmol) in degassed THF (4.5 mL)was treated with a catalytic amount (80 mg, 69 mmol) oftetrakis(triphenylphosphine) palladium (0) and the suspension wasstirred at 25° C., under Ar for 30 min. The resulting bright yellow,homogeneous solution was treated all at once with a solution of sodiumazide (54 mg, 0.83 mmol) in degassed H₂O (2.2 mL). The reaction mixturewas warmed to 45° C. for 1 h, diluted with H₂O (5 mL) and extracted withEtOAc (4×7 mL). The organic extracts were washed with saturated aqueousNaCl (15 mL), dried (Na₂SO₄), and concentrated in vacuo. The residue waspurified by flash chromatography (SiO₂, 3.0×15 cm, 95:5.0:0.5CHCl₃—MeOH—AcOH) to afford Compound A (0.23 g, 61%) as a colorless oil.MS (ESI⁺): 551 (M+H)⁺; MS(ESI⁻): 549 (M−H)⁻.

B.(3S,6R,7S,8S,12R,13S,15S)-15-Amino-12,13-epoxy-4,4,6,8,12,16-hexamethyl-7-hydroxy-17-(2-methyl-4-thiazolyl)-5-oxo-16-heptadecenoicacid

A solution of Compound A (0.23 g, 0.42 mmol) in THF (4.0 mL) was treatedwith H₂O (23 mL, 1.25 mmol) and polymer supported triphenylphosphine(Aldrich, polystyrene cross-linked with 2% DVB₁ 0.28 g, 0.84 mmol) at25° C. The resulting suspension was stirred at 25° C. under Ar (32 h),filtered through a Celite pad and concentrated in vacuo. The residue waspurified by flash chromatography (SiO₂, 1.5×10 cm, 95:5.0:0.5 to90:10:1.0 CHCl₃—MeOH—AcOH gradient elution) to afford Compound B (96 mg,44%) as a colorless oil. MS (ESI⁺): 525.2 (M+H)⁺; MS(ESI⁻): 523.4(M−H)⁻.

Alternatively, to a 25 mL round-bottom flask charged with Compound A(0.26 g, 0.47 mmol) and PtO₂ (0.13 g, 50 wt %) was added absolute EtOHunder Ar. The resulting black mixture was stirred under one atmosphereof H₂ for 10 h, after which time the system was purged with N₂ and anadditional portion of PtO₂ (65 mg, 25 wt %) was added. Once again thereaction mixture was stirred under a blanket of H₂ for 10 h. The systemwas then purged with N₂, and the reaction mixture was filtered through aCelite pad eluting with CH₂Cl₂ (3×25 mL). The solvents were removed invacuo and the residue was purified as described above to afford CompoundB (0.19 g, 75%).

Alternatively, a solution of Compound A (20 mg, 36 mmol) in THF (0.4 mL)was treated with triphenylphosphine (19 mg, 73 mmol) under Ar. Thereaction mixture was warmed to 45° C., stirred for 14 h and cooled to25° C. The resulting iminophosphorane was treated with ammoniumhydroxide (28%, 0.1 mL) and once again the reaction mixture was warmedto 45° C. After 4 h, the volatiles were removed in vacuo and the residuewas purified as described above to afford Compound B (13 mg, 70%).

C.[1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-Dihydroxy-8,8,10,12,16-pentamethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-4-aza-17-oxabicyclo[14.1.0]heptadecane-5,9-dione

A solution of Compound B (0.33 g, 0.63 mmol) in degassed DMF (250 mL)was treated with solid NaHCO₃ (0.42 g, 5.0 mmol) and diphenylphosphorylazide (0.54 mL, 2.5 mmol) at 0° C. under Ar. The resulting suspensionwas stirred at 4° C. for 24 h, diluted with phosphate buffer (250 mL,pH=7) at 0° C. and extracted with EtOAc (5×100 mL). The organic extractswere washed with 10% aqueous LiCl (2×125 mL), dried (Na₂SO₄) andconcentrated in vacuo. The residue was first purified by flashchromatography (SiO₂, 2.0×10 cm, 2-5% MeOH—CHCl₃ gradient elution) andthen repurified using a Chromatotron (2 mm SiO₂, GF rotor, 2-5%MeOH—CHCl₃ gradient elution) to afford the title compound (0.13 g, 40%)as a colorless oil. ¹H NMR (CDCl₃, 400 MHz) δ 6.98 (s, 1H), 6.71 (d, 1H,NH, J=8.1 Hz), 6.56 (s, 1H), 4.69-4.62 (m, 1H), 4.18-4.12 (m, 1H),4.01-3.96 (m, 1H), 3.86 (s, 1H), 3.38-3.34 (m, 1H), 2.82 (dd, 1H, J=5.6,6.0 Hz), 2.71 (s, 3H), 2.58 (s, 1H), 2.43 (dd, 1H, J=9.0 14.5 Hz), 3.34(dd, 1H, J=3.0, 14.5 Hz), 2.14 (s, 3H), 2.05-1.92 (m, 2H), 1.82-1.41 (aseries of multiplets, 7H), 1.35 (s, 3H), 1.28 (s, 3H), 1.18 (d, 3H,J=6.8 Hz), 1.14 (s, 3H), 1.00 (d, 3H, J=6.8 Hz); MS (ESI⁺): 507.2(M+H)⁺; MS(ESI⁻): 505.4 (M−H)⁻.

Example 4 Process for Reduction of Oxirane Ring of Epothilone andEpothilone Analogs

To a two-necked flask was added chopped pieces of magnesium turnings (24mg, 1.0 mmol). The flask was flame-dried under vacuum and cooled underargon. Bis(cyclopentadienyl)titanium dichloride (250 mg, 1.0 mmol) wasadded followed by anhydrous THF (5 mL). The stirring suspension wasevacuated with low vacuum, and the reaction flask was refilled withargon. The red suspension became dark, turning a homogeneous deep greenafter 1.5 h with nearly all the magnesium metal being consumed. Analiquot (3.5 mL, 0.70 mmol, 3.5 eq) was removed and cooled to −78° C.under argon. To this solution was added epothilone A (99 mg, 0.20 mmol,1.0 eq). The reaction mixture was warmed to room temperature and stirredfor 15 min. The volatiles were removed in vacuo and the residue waschromatographed two times on silica (25 g), eluting with 35%EtOAc/hexanes to give 76 mg (80%) of epothilone C as a pale yellowviscous oil.

Example 5

[1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-Dihydroxy-8,8,10,12-tetramethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-4-aza-17-oxabicyclo[14.1.0]heptadecane-5,9-dione A.(3S,6R,7S,8S,12R,13S,15S)-15-Azido-3,7-dihydroxy-12,13-epoxy-4,4,6,8,16-pentamethyl-17-(2-methyl-4-thiazolyl)-5-oxo-16(E)-heptadecenoicacid

Tetrakis(triphenylphosphine)palladium(0) (1.17 g, 1.01 mmol, 0.10 eq)was added to a solution of epothilone A (4.97 g, 10.1 mmol, 1.0 eq) indegassed THF (100 ml) at room temperature and was stirred for 30 minutesunder argon. Sodium azide (0.980 g, 15.1 mmol, 1.5 eq) was added to theabove reaction mixture followed by the addition of degassed water (10ml). The reaction mixture was heated to 45° C. for one hour, cooled toroom temperature, diluted with ethyl acetate (300 ml) and furtherdiluted with water (150 ml). The aqueous layer was extracted with ethylacetate (3×100 ml). The combined organic extracts were washed with brine(150 ml), dried (sodium sulfate), filtered and concentrated undervacuum. The oily residue was purified by flash silica gel chromatography(eluting 0-5% methanol/chloroform with 0.1% of acetic acid) to affordCompound A (1.84 g, 34.0% yield) as glassy solid. MS (ESI⁺): 537 (M+H)⁺;MS (ESI⁻): 535 (M−H)⁻.

B.(3S,6R,7S,8S,12R,13S,15S)-15-Amino-3,7-dihydroxy-12,13-epoxy-4,4,6,8,16-pentamethyl-17-(2-methyl-4-thiazolyl)-5-oxo-16(E)-heptadecenoicacid

Platinum oxide (0.980 g, 4.30 mmol, 1.25 eq) was added to a solution ofCompound A (1.85 g, 3.44 mmol, 1.0 eq) in absolute ethanol (137 ml). Thereaction mixture was stirred vigorously under a hydrogen balloon for 16hours at room temperature. The reaction mixture was filtered and thefiltrate was concentrated under vacuum. The oily residue was purified bypreparative HPLC (YMC S-15 ODS 50×500 mm column, 45 minutes/gradient,0-100% B, 50 ml/min, retention time=17 minutes, A=0.1% acetic acid/5%acetonitrile/95% water, B=0.1% acetic acid/5% water/95% acetonitrile).The appropriate fractions were concentrated under vacuum and the residuewas lyophilized from aqueous acetonitrile to afford Compound B (1.33 g,76.0% yield) as a colorless solid. MS (ESI⁺): 511(M+H)⁺; MS (ESI⁻): 509(M−H)⁻.

C.[1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-Dihydroxy-8,8,10,12-tetramethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-4-aza-17-oxabicyclo[14.1.0]heptadecane-5,9-dione

Compound B (0.860 g, 1.68 mmol, 1.0 eq) was dissolved in anhydrous DMF(0.00250M, 672 ml) and degassed for one hour at room temperature. Thesolution was cooled to 0° C., and anhydrous sodium bicarbonate (1.13 g,13.4 mmol, 4.0 eq) and diphenylphosphoryl azide (1.85 g, 6.72 mmol, 8.0eq) were added under argon. The reaction mixture was kept at 4° C. underargon and stirred 16 hours. The reaction mixture was then cooled to −60°C., and pH 7 phosphate buffer (400 ml) was added slowly to quench thereaction. Temperature was kept below −30° C. The above mixture wasallowed to warm to room temperature slowly and extracted with ethylacetate (1 liter). The aqueous layer was washed with ethyl acetate(4×300 ml). The organic extracts were combined, washed with 10% LiCl(500 ml), dried (sodium sulfate), filtered and concentrated undervacuum. The oily residue was purified by preparative HPLC (YMC S-15 ODS50×500 mm column, 45 minutes/gradient, 0-100% B, 50 ml/min, retentiontime=35 minutes, A=5% acetonitrile/95% water, B=5% water/95%acetonitrile). The appropriate fractions were concentrated under vacuumand the residue was lyophilized from aqueous acetonitrile to affordtitle compound (0.220 g, 26.0% yield) as a colorless solid. MS (ESI⁺):493 (M+H)⁺, MS (ESI⁻): 491 (M−H)⁻.

Example 6

[4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-Dihydroxy-5,5,7,9,13-pentamethyl-16-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-1-aza-13(Z)-cyclohexadecene-2,6-dione

Tungsten hexachloride (0.19 g, 0.49 mmol, 0.5 equiv) was dissolved inTHF (5.0 ml) and the solution was cooled to −78° C. n-Butyllithium inhexane (1.6M, 0.63 ml, 1.0 mmol, 1.0 equiv) was added in one portion andthe reaction mixture was allowed to warm to room temperature over 20minutes (the solution turned dark green upon warming to rt). A 0.1Msolution of the prepared tungsten reagent (0.79 ml, 0.079 mmol, 2.0mmol) was added to Compound 4C (0.020 g, 0.039 mmol, 1.0 equiv) at roomtemperature. The reaction mixture was stirred a room temperature for 30minutes and then was quenched with saturated NaHCO₃ (2.0 ml). Thequenched solution was diluted with water (10 ml) and the solution wasextracted with CH₂Cl₂ (4×20 ml). The combined organic extracts weredried (Na₂SO₄), filtered and concentrated under vacuum. The inorganicswere removed by passing the residue through a silica gel plug (elutingwith 19/1 CHCl₃/MeOH). The eluent was concentrated under vacuum. Theresidue was purified by phplc (YMC-S5 ODS, 30-100% B, A=5% aq CH₃CN,B=95% aqueous CH₃CN, 3 ml/min., 220 nm., 30 min. gradient) and theappropriate fractions were concentrated under vacuum. The sticky solidwas lyophilized from aqueous acetonitrile to afford title compound (4.3mg, 29%) as a white solid. TLC: Rf=0.57 (9/1 CHCl₃/MeOH, visualizationby UV); HRMS: (M+H)⁺ calc=491.29436, found=491.2934.

Example 7

[1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-Dihydroxy-8,8,10,12,16-pentamethyl-3-[1-methyl-2-(2-hydroxymethyl-4-thiazolyl)ethenyl]-4-aza-17-oxabicyclo[14.1.0]heptadecane-5,9-dione

A.[1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-Dihydroxy-8,8,10,12,16-pentamethyl-3-[1-methyl-2-(2-methyl-4-thiazolyl)ethenyl]-4,17-dioxabicyclo[14.1.0]heptadecane-5,9-dione,N-oxide

A solution of epothilone B (2.0 g, 3.9 mmol) in CH₂Cl₂ (30 mL) wastreated with 3-chloroperoxybenzoic acid (1.0 g, 5.9 mmol) at 25° C.,under Ar for 2 h. An additional 0.5 g (3.0 mmol) of3-chloroperoxybenzoic acid was added and the reaction mixture was thenstirred for 2 h. The reaction mixture was filtered and the filtrate wasconcentrated in vacuo. The residue was dissolved in EtOAc (100 mL),washed with saturated aqueous NaHCO₃ (75 mL), 5% aqueous Na₂SO₃ (75 mL),H₂O (75 mL), dried (Na₂SO₃) and concentrated in vacuo. The residue waspurified by flash chromatography (SiO₂, 4.5×30 cm, 2-10% MeOH—CHCl₃gradient elution) to afford Compound A (1.04 g, 50%) as a white solid.MS (ESI⁺): 524.3 (M+H)⁺; MS (ESI⁻): 522.5 (M−H)⁻.

B.[1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-Dihydroxy-8,8,10,12,16-pentamethyl-3-[1-methyl-2-(2-hydroxymethyl-4-thiazolyl)ethenyl]-4,17-dioxabicyclo[14.1.0]heptadecane-5,9-dione [Epothilone F]

To a solution of Compound A (0.46 g, 0.88 mmol) in CH₂Cl₂ (10 mL) in aresealable tube was added 2,6-lutidine (0.82 mL, 7.0 mmol) andtrifluoroacetic anhydride (0.87 mL, 6.2 mmol) under Ar. The reactionvessel was sealed under Ar, heated to 75° C. (12 min), cooled to 25° C.,and the volatiles were removed under a steady stream of N₂. The reactiontube was then placed on a high vacuum pump for 15 min. The resultingresidue was dissolved in MeOH (10 mL) and treated with ammoniumhydroxide (28-30% NH₄ in H₂O, 1.0 mL). The mixture was heated to 45° C.(10 min), and the volatiles were removed in vacuo. The crude reactionmixture was purified by HPLC (YMC S-15 ODS 30×500 mm column, 50%acetonitrile-H₂O isocratic conditions, flow rate=20 mL/min, retentiontime=28 min). The appropriate fractions were concentrated under vacuumand the residue was lyophilized from aqueous acetonitrile to affordCompound B (0.22 g, 48%) as a white solid. MS (ESI⁺): 524.3 (M+H)⁺,1047.6 (2M+H)⁺; MS (ESI⁻): 522.5 (M−H)⁻.

C.(3S,6R,7S,8S,12R,13S,15S)-15-Azido-3,7-Dihydroxy-12,13-epoxy-4,4,6,8,12,16-hexamethyl-17-(2-hydroxymethyl-4-thiazolyl)-5-oxo-16(E)-heptadecenoicacid

A solution of Compound B (0.18 g, 0.34 mmol) in degassed THF (3.0 mL)was treated with a catalytic amount (40 mg, 3.4×10⁻² mmol) oftetrakis(triphenylphosphine) palladium(0) and the suspension was stirredat 25° C., under Ar for 30 min. The resulting bright yellow, homogeneoussolution was treated all at once with a solution of sodium azide (27 mg,0.41 mmol) in degassed H₂O (1.5 mL). The reaction mixture was warmed to45° C. for 1 h, diluted with H₂O (5 mL) and extracted with EtOAc (4×10mL). The organic extracts were washed with saturated aqueous NaCl (15mL), dried (Na₂SO₄), and concentrated in vacuo. The residue was purifiedby flash chromatography (SiO₂, 2.5×15 cm, 95:5 CHCl₃—MeOH to 95:5.0:0.5CHCl₃—MeOH—AcOH gradient elution) to afford Compound C (39 mg, 20%) as acolorless oil. MS (ESI⁺): 567.4 (M+H)⁺, 1133.6 (2M+H)⁺; MS (ESI⁻): 565.5(M−H)⁻, 1131.8 (2M−H)⁻.

D.(3S,6R,7S,8S,12R,13S,15S)-15-Amino-3,7-dihydroxy-12,13-epoxy-4,4,6,8,12,16-hexamethyl-17-(2-hydroxymethyl-4-thiazolyl)-5-oxo-16(E)-heptadecenoicacid

To a 10 mL round-bottom flask charged with Compound C (40 mg, 71 mmol)and PtO₂ (12 mg, 30 wt %) was added absolute EtOH (3 mL) under Ar. Theresulting black mixture was stirred under one atmosphere of H₂ for 10 h.The system was then purged with N₂ and the reaction mixture was filteredthrough a nylon membrane (washing with 25 mL of MeOH). The solvents wereremoved in vacuo to afford Compound D (29 mg, 76%) as a foam, which wassufficiently pure to use in the next step. LCMS: 541.3 (M+H)⁺.

E.[1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-Dihydroxy-8,8,10,12,16-pentamethyl-3-[1-methyl-2-(2-hydroxymethyl-4-thiazolyl)ethenyl]-4-aza-17-oxabicyclo[14.1.0]heptadecane-5,9-dione

A solution of Compound D (29 mg, 54 mmol) in degassed DMF (21 mL) wastreated with solid NaHCO₃ (36 mg, 0.43 mmol) and diphenylphosphorylazide (46 mL, 0.21 mmol) at 0° C. under Ar. The resulting suspension wasstirred at 4° C. for 19 h, cooled to −40° C., diluted with 25 mL of pH 7phosphate buffer (carefully adding such that the internal temperatureremains below −30° C.), and extracted with EtOAc (4×10 mL). The organicextracts were washed with cold 10% aqueous LiCl (25 mL), dried (Na₂SO₄)and concentrated in vacuo. The residue was purified using a chromatotron(1 mm SiO₂ GF rotor, 2-5% MeOH—CHCl₃ gradient elution) to afford thetitle Compound E (9.1 mg, 34%) as a colorless oil. MS (ESI⁺): 523.2(M+H)⁺; MS (ESI⁻): 521.5 (M−H)⁻.

Example 8

[4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-Dihydroxy-5,5,7,9,13-pentamethyl-16-[1-methyl-2-(2-hydroxymethyl-4-thiazolyl)ethenyl]-1-aza-13(Z)-cyclohexadecene-2,6-dione

A.[1S-[1R*,3R*(E),7R*,10S*,11R*,12R*,16S*]]-7,11-Dihydroxy-8,8,10,12,16-pentamethyl-3-[1-methyl-2-(2-tert-butyldiphenylsilyloxymethyl-4-thiazolyl)ethenyl]-4-aza-17-oxabicyclo[14.1.0]heptadecane-5,9-dione

A solution of Compound 7E (6.8 mg, 13 mmol) in CH₂Cl₂ (0.5 mL) wastreated with triethylamine (2.7 mL, 20 mmol),4-N,N-dimethylaminopyridine (0.2 mg, 1.3 mmol) andtert-butyldiphenylsilyl chloride (3.7 mL, 14 mmol) at 0° C. under Ar.The reaction mixture was gradually warmed to 25° C. (1 h), cooled to 0°C., quenched by the addition of saturated aqueous NaHCO₃ (1 mL), andextracted with EtOAc (4×2 mL). The combined organic extracts were washedwith brine (5 mL), dried (Na₂SO₄) and concentrated in vacuo. The residuewas purified by flash chromatography (SiO₂, 1.0×5 cm, 2-5% MeOH—CHCl₃gradient elution) to afford Compound A (7.0 mg, 71%) as a colorless oil.MS (ESI⁺): 761.5 (M+H)⁺; MS (ESI⁻): 759.7 (M−H)⁻.

B.[4S-[4R*,7S*,8R*,9R*,15R*(E)]]-4,8-Dihydroxy-5,5,7,9,13-pentamethyl-16-[1-methyl-2-(2-hydroxymethyl-4-thiazolyl)ethenyl]-1-aza-13(Z)-cyclohexadecene-2,6-dione

A solution of tungsten(IV) chloride (0.10 g, 0.25 mmol) in anhydrous THFat −78° C. was treated with n-BuLi (1.6 M in hexanes, 0.32 mL, 0.50mmol) under Ar. The reaction mixture was warmed to 25° C. over 40 minand then recooled to 0° C. An aliquot of the resulting deep-green,homogeneous solution (0.2 mL, 20 mmol) was added to a 1 dram vialcharged with Compound A (7.0 mg, 9.2 mmol) at 0° C. under Ar. Thereaction mixture was warmed to 25° C., stirred for 30 min, quenched bythe addition of saturated aqueous NaHCO₃ (0.5 mL) and extracted withEtOAc (4×1 mL). The combined organic extracts were dried (Na₂SO₄) andconcentrated in vacuo. The residue was purified by preparative TLC(SiO₂, 20×20×0.025 cm, eluting with 5% MeOH—CHCl₃) to afford aninseparable mixture of the silyl-protected (13Z) isomer of Compound Balong with a small amount (<10%) of the minor (13E) isomer, which wasimmediately deprotected in the next step.

The silyl-protected isomeric mixture of Compound B (2.3 mg, 3.1 mmol)was treated with 0.3 mL of a buffered solution of HF-pyridine in THF(2:1:0.5 THF/pyridine/HF-pyridine solution from Aldrich Chemical Co.) at25° C. After 1 h, the reaction mixture was neutralized with saturatedaqueous NaHCO₃ (0.5 mL) and extracted with EtOAc (4×1 mL). The combinedorganic extracts were washed with saturated aqueous NaHCO₃ (1 mL), dried(Na₂SO₄) and the volatiles were removed in vacuo. The residue waspurified by preparative TLC (SiO₂, 20×10×0.025 cm, eluting with 5%MeOH—CHCl₃) to afford title compound (13Z-isomer) along with aninseparable amount (<10%) of the minor (13E) isomer (0.96 mg, 20% forthe two steps) as a thin film. MS (ESI⁺): 507.3 (M+H)⁺; MS (ESI⁻): 505.6(M−H)⁻.

We claim:
 1. A compound having the formula V,

wherein G is bicycloheteroaryl; R₃, R₄, R₅, R₆, and R₇ are selected fromthe group consisting of H, alkyl, substituted alkyl, and aryl; and R₈ isH, alkyl, substituted alkyl, aryl, substituted aryl, cycloalkyl, orheterocyclo.
 2. A compound according to claim 1 wherein G isbicycloheteroaryl selected from benzothiazolyl, benzoxazolyl,benzothienyl, quinuclidinyl, quinolinyl, quinolinyl-N-oxide,tetrahydroisoquinolinyl, isoquinolinyl, benzimidazolyl, benzopyranyl,indolizinyl, benzofuryl, chromonyl, coumarinyl, cinnolinyl,quinoxalinyl, indazolyl, pyrrolopyridyl, furo[2,3-c]pyridinyl,furo[3,1-13]pyridinyl, furo[2,3-b]pyridinyl, dihydroisoindolyl,3,4-dihydro-4-oxo-quinazolinyl, benzisothiazolyl, benzisoxazolyl,benzodiazinyl, benzofurazanyl, benzothiopyranyl, benzotriazolyl,benzpyrazolyl, dihydrobenzofuryl, dihydrobenzothienyl,dihydrobenzothiopyranyl, dihydrobenzothiopyranyl sulfone,dihydrobenzopyranyl, indolinyl, isochromanyl, isoindolinyl,naphthyridinyl, phthalazinyl, piperonyl, purinyl, pyridopyridyl,quinazolinyl, tetrahydroquinolinyl, thienofuryl, thienopyridyl, andthienothienyl.
 3. A compound according to claim 2 wherein G isbenzothiazolyl.